The monitoring of movements of monitored individuals involves a variety of sectors, including parolees and home confinement. The technology has its roots in the home arrest systems of the 1980's, in which a user wearable component—typically a “beacon” anklet that was locked to the monitored individual—would communicate wirelessly with a stationary base unit. The range was limited to a few feet of the radio frequency transmitter and receiver. The base unit included a telephone connection for communicating with the authorities. If the monitored individual left the short range allowed by the equipment, the tag and the base unit would lose contact and the base unit would respond by sending an alert to the authorities. False alarms for minor deviations from the short range and/or an inability to confirm false from actual alarms (if the person was where they were supposed to be when the police arrived to investigate) desensitized the police to such alerts, rendering the technology of limited application to low risk offenders.
A later generation of the technology incorporated GPS and cellular telephone technology in a locked anklet. The device would actively record the location of the monitored individual over time and transmit the data to a central monitoring location (e.g., police or parole monitoring services). The central location could store and analyze the data for prohibited movements (e.g., a sex offender near a school) or cross reference the movement data with crime incident data to see if the monitored individual was near the crime at the time of the crime. U.S. Pat. Nos. 5,867,103, 6,160,481, 6,218,945, 6,512,456 and 6,703,936, incorporated herein by reference in their entireties, are each exemplary of such a system. The technology is also used to monitor other individual sectors (e.g., patients, children) and objects (e.g., cars, cargo).
The modern monitoring device includes a GPS receiver that determines location, a memory that stores location data over time to define a movement history, and a cellular modem that communicates the movement history to a central location through the cell network. A common implementation is in the criminal justice system as an alternative to incarceration, and monitored individuals (typically parolees) have tamper resistant devices attached to their leg by a band. For ease of discussion embodiments herein are directed to parolees, although the invention is not so limited.
Often a condition of parolee is that a parolee wears a personal monitoring device, and removal of the monitoring device (e.g., cutting the band that attaches it to the leg) is a parole violation that could result in revocation of parole and subsequent re-incarceration. In some jurisdictions the removal of the monitoring device is itself an independent crime and can result in additional charges and jail time. To avoid these potential consequences the overwhelming bulk of the monitored parolee population makes no effort to remove the monitoring device.
Nonetheless there are occasional violations. Once a parolee cuts the monitoring device and leaves it behind, options for locating the parolee are limited. At an electronic level, in theory the supervising authority can obtain a warrant for the cell carrier to provide the current location of the phone, but this takes time and is not useful if the parolee either does not have the phone (e.g., left it behind, switched to a burner phone). Otherwise the supervising authority is limited to standard police investigate procedures.